An electronic device included a first energy storage device coupled to a second energy storage device by a conductor. A charging node is coupled to the first energy storage device. Another conductor couples the charging node to the second energy storage device. A switch is electrically coupled between the conductor and the second energy storage device. A control circuit opens the switch, thereby allowing a first charging current to flow from the charging node to the first energy storage device through the conductor and a second charging current to flow from the charging node to the second energy storage device through the other conductor and closes the switch when a difference between a voltage of the first energy storage device and a voltage of the second energy storage device is within a predefined voltage difference threshold.